Hydraulic apparatus



(No Model.) 2 sheets-sheen 1. E. T. ROBB. HYDRAULIC APPARATUS.

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(No Model.) 2 sheets-sheet 2.

E. T. ROBB.

HYDRAUMG APPARATUS.

No. 433,822.' 3 Patented Aug. 5, 1890.

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into the rear end of the cylinder is controlled UNITED STATES- 'PAT-ENT OFFICE.

ELIAKIMCT. ROBB, OF CHESTER, ASSIGNOR OF ONE-HALF TO LEWIS MILLER,

` OF PHILADELPHIA, PENNSYLVANIA.

APPARATUS.

SPECIFICATION forming vpart of Letters Patent No. 433,822, dated August' 5, 1890.

Application nea raam 5, i899.

To 1f/ZZ whom, it may concern.-

Be it known that I, ELIAKIM T. RoBB,-al citizen of the United States, residing at Ches-v ter, in the county of Delaware and State of Pennsylvania, have invented certain new and useful Improvem en ts in Hydraulic Apparatus, of which the following is a specification, reference being had therein to the accompanying' drawings, in which- Figure 1 represents a vertical longitudinal sectional View of my improved hydraulic apparatus for punching or pressing; Fig. 2, a side elevation, p artly in section, of the large steam-cylinder employed to operate the ram;` Figs. 3, 4, and 5, detail sectional views of the rotary valve employed to govern the admission of steam to the said cylinder; Fig. 6, a, detail view of the valve-arm of the valve of the auxiliary cylinder.

The invention is an apparatus for operating hydraulic presses, punches, dre.; and it has for its objects the production of a comparatively simple apparatus, which shall be automatic in action and which will perform very heavy work with but a minimum expenditure of fuel, as will be more fully hereinafter described.

In the drawings annexed, A designates a hydraulic punch of suitable construction. In this instance the punch consists of upper stationary platen carrying the punches and a lower movable platen carrying the dies and operated by suitable hydraulic cylinders connected to the supply-conduit a. Located within a convenient distance of the punch is a hydraulic cylinder B,having both of its ends closed by suitable heads and connected near its ends with the main conduit a by short The conduit leading' by a vertical working check-valve b, the stem lof 'which passes out through a suitable bushlng in the conduit, and is connected to the short horizontal arm of a pivoted an gle-lever c. Vorking in the cylinder B is a piston B', connected to a piston-rod C, which passes out Athrough a suitable stuihng-box in the head of the cylinder. Connected to the forward face of the piston B and surrounding an extension of the piston-rod is a rod or cylinder D,`which is nearly as great in diameter as the sain Nfeaze. l (No modem piston and which passes out through a suitable stufng-box in the head of the cylinder. As thus constructed, it will be observed that the two faces of the piston are unequal in pressing-area, the front side of the piston having but a small area (depending upon the relative diameters of the piston "and rod D) and its front side the larger area.

A large steam-cylinder E is secured upon the same base with the hydraulic cylinder and connected rigidly thereto by strongrods d, the piston E of this cylinder beingl connected directly to the piston-rodof the hydraulic cylinder. Connected to the rear side of the piston E and extending out through the head of thecylinder is a hollow rod F, which is larger in diameter lthan the pistonrod; By thus providingtlie piston with a rearwardly-extending r'od of greater diameterl than the piston-rod, it will be seen that the area of the front side of the piston will be greater than the area of its rear side, and for this reason when both sides of the piston are subjected at the same time to steam under a uniform pressure, the preponderance ofpressure Will be exerted upon the front side of the piston (the side having the greatest area)- and thereby force the same to the .rear end of the cylinder, as will be more fully hereinafter set forth.

, The ports e e of the cylinder lead into a valve-chamber G', wherein works a rotary valve @provided with a transverse passage f through it, which passage at certain periods registers with and establishes communication between the two ports c e, as shown in Fig. 5, for a purpose hereinafter stated.

The stem of valve G has secured upon it an angle armor lever g, the upper end of which is connected by means of suitable system of rods and angle-levers g to a vertical movable bar g, secured on the punch-frame and adapted to be depressed every time the lower platen falls, whereby the said valve G will be rotated a sufiicient distance to cause the valve-passage f to register with and connect the ports of the cylinder, for the purr pose hereinafter explained.`

Projecting into the cylinder E, through suitable stuffing-boxes in its heads, are two rods h, which engage arms on two rock-shafts IOO h', journaled in suitable brackets bolted to the respect-ive ends of the cylinder. The forward rod 71l also 'engages the lower end of the vertical arm of the angle-lever c, whereby when the said rod h is moved in a forward direction by the piston E the said angle-lever will be caused to automatically raise the valve b from its seat and holdit up until the said piston recedes.

Mounted on the exterior of the cylinder E, near one of its ends, is a supplemental cylinder H, provided with a piston H and a rotary Valve H to govern the admission and emission of steam. The piston has connected to it a horizontal rod t', which extends out through a stuffing-box in thehead of the cylinder, and is provided-with a horizontal slot for the reception of the lower end of the angle-lever g, the said slot being long enough to allow the rod fi to move independently of the angle-lever for about one-half its stroke.

The stem of the valve H, as shown in dotted lines in Fig. 2 and in full lines in Fig. G, is provided with a depending arm j, which is pivotally connected to two oppositely-projecting rods lr., which are in turn connected pivotally to arms on the rock-shafts 7L h. By this arrangement it will be perceived that when the piston E forces the forward rod 7L forward this rod not only raises the checkvalve ZJ, but it also, through the medium of the rock-shaft h and its arms, rod 7e', and arm j, rotates the valve H sufficien tly to permit live steam to pass in behind the piston H and the exhaust-steam to make itsl exit through the exhaust-port. When the piston E moves toward the other end of the cylinder,it will force the other rod 72, outward, and the movement of the valve H will be thereby reversed through the medium of the connecting-rods and arms, as is evident.

The operation, brieiiy, is as follows: Before starting the apparatus the pistons E and B rest at the forward ends of their respective cylinders and lower movable platen of the punch or press is down. Vhen steam is admitted in front of the piston IC, this piston moves backward and draws the piston B to the rear end of its cylinder, thereby forcing a sufficient quantity of the pressing-liquid into the cylinders of the punching apparatus to raise the lower platen until the punches come in contact or nearly so with the plate to be punched, whereupon the check-valve will close and prevent backflow of the pressing-liquid. As the piston B thus moves rearward, a portion of the liquid of course is drawn into the cylinder B in front of the piston. Vhen the piston E lreaches the rear end of its cylinder, it forces the tappet-rod h out and thereby rotates the supplemental valve H far enough toadmit steam into the `rear end of the cylinder IVI, whereupon the piston H will be forced to the forward end of its cylinder and its piston-rod will cause the valve-arm g to assume the position shown by dotted lines 8 3 of Fig. 2, thereby rotating the valve G to the position shown in Fig. 4. The fresh steam will then rush in behind the piston E and force the same forward, the steam in front of this piston making its escape through the exhaust-ports of valve, as usual'. As the steam-piston moves forward, avacuum will be created behind the piston B and the liquid in front of this piston and surrounding the rod D will be forced out through the forward passage a into the cylinders of the punch, thereby forcing up the lower platen against the punches and causing` the same to pass through the plate resting on the dies. It will thus be seen that by means of the single hydraulic cylinder B and differential piston B, I am enabled to accomplish the initial light pressure and iinal heavy pressure, the rearward movement of the piston serving to lill the cylinders of the punch or press and the forward movement of the piston serving to perform the heavy work of forcing the punches through the plate. This improvement it will be perceived avoids the use of the two hydraulic rams heretofore employedone for furnishingthe light pressure and the otherfor furnishing the'nal heavy pressure. When the punches have passed through the plate and the pistons reach the forward end of their respective strokes, the steam-piston will automatically force the tappet-rod h forward and raise the check-valve Z) and permit the press-k ing-liquid to iiow back into the rear end of the cylinder B, the liquid being forced back into the cylinder by the gravitation of the lower platen of the punch or press. At the same instant that the piston E opens the valve b it also (through the medium of parts 71., 7i', and 7c) shifts the valve H far enough to let steam into the forward end of cylinder H, and thereby drive the piston H to the rear end of its cylinder, whereupon the slotted rod will cause the valve-arm g and valve G to assume the position shown in Figs. 1 and 3, thereby shutting off the ,supply of steam to the main cylinder. Vhile the lower platen is descending,` the operator removes the punched plate and inserts another, as is evident. The pistons will remain at the forward ends of their strokes until the platen of punch or press has fallen far enough to force down the rod g, whereupon the valve-arm g (through the medium of the rods and anglelevers g) will be shifted to the position shown by dotted lines I I of Fig. 2, and the valve to the position shown in Fig. 5, the slot in said rod t' being long enough to permit this independent movement of the arm g. The instant the valve G assumes the position shown in Fig. 5 the steam in the rear of the steam-piston exhausts through the ports e and passage f into the forward end of the cylinder in front of the piston. By reason of the fact that the area of the front side of the piston is greater than that of its rearl side, the result of exhausting the steam into the forward end of the cylinder (by reason of the differential pressure thus created) will be to force the IOO IIO

piston back again to the rear end of the cylinder, thereby refilling the cylinders of the punch and again raising its platen up to the punches ready for the heavy pressure to force the same through the Work, and so on through each successive' operation.

The advantages of thus utilizing the eX- haust-steam employed in performing the heavy pressing 'operation for accomplishing I pressing areas, and means for operating the said piston, substantially as described.

2. The combination of a hydraulic cylinder having conduits leading out of its ends, a differential piston B', Working in said cylinder, a check-valve b in one of the said conduits, an angle-lever c, connected to the said valve, a steam-cylinder connected to the said hydraulic cylinder, a piston Working in this steam-cylinder and having its rod connected to the said hydraulic piston, a sliding rod 71 extending into the steam-cylinder and connected to the angle-lever c, a valve for admitting steam to the said cylinder, and means, substantially as described, for operating this valve simultaneously with the said valve b, substantially as set forth.

3. The combination of a steam-cylinder, a piston Working in this cylinder and provided with a piston-rod C, a rod F, connected to the rear side of the piston and extending out through the rear end of the cylinder, this rod being of a different diameter than the said piston-rod, a hydraulic cylinder having conduits leading out of its ends, a differential piston in this cylinder and connected to the said steam-piston rod, as'and for the purpose described.

4. The combination, with a press or punch or other hydraulic-apparatus, of a hydraulic cylinder having conduits leading out of its respective ends and connected to the said press or punch, ak check-valve b in one of these conduits, a differential piston Working in the hydraulic cylinder, a steam-cylinder connected t0 the hydraulic cylinder and provided with a valve-box G, a dierential piston Working in this cylinder and connected to the hydraulic piston, a rotary valve G, Working in the valve-box G and provided with apassage f through it, and means for operating the said valves b and G simultaneously, substantially as described.

5. The combination of the hydraulic cylinder and conduits leading therefrom, a differential piston working in said cylinder, a-

steam-cylinder provided with a valve G, a/ differential piston working in this cylinder and connected to the hydraulic piston, a supplemental cylinder H, provided with a val ve, a piston in this cylinder provided vvith a piston-rod t', an arm connecting this rod t' to the said valve G, and means for operating the valve ot' the said cylinder H, substantially as and for the purpose described.

In testimony whereof I affix my signature in presence of two witnesses.

ELIAKIM T. ROBB. Witnesses:

J oHN T. LEIPER, J. WALTER LINDSAY. 

